These novel products, which measure both TCO sheet resistance and layer thickness at full production speeds are ideally suited for industrial applications in the rapidly developing HJT cell manufacturing market. The technology will be showcased at SNEC 2018.

Problem

To produce the electrical structure of a HJT cell, it is necessary to apply thin layers of amorphous silicon on both sides of a crystalline silicon wafer as well as transparent, conductive oxide layers (TCO) to absorb the generated power. The TCOs are the conduits allowing electrical current to flow from the active portion of the cell to the metal contacts. Optimizing and controlling the uniformity of the TCO layers during cell manufacturing is crucial to maximizing the power and yield of the HJT cells.

Solution

The DM-121 and DM-321 systems measure the front and rear TCO sheet resistances and thicknesses on silicon photovoltaic (PV) wafers. Both sheet resistance and thickness are measured at a series of discrete points along each wafer. Aurora’s patented non-contact infrared measurement technology is used in these products and provides accurate real-time measurements for process control and optimization.

Applications

The DM-121 and DM-321 systems measure the front and rear TCO sheet resistances and thicknesses of heterojunction solar cells.

Platform

The systems consists of a specialized pair of DM (formerly Decima) series measurement heads, designed as a unit to fit above and below a wafer conveyor. They measure up to 100 percent of wafers at full production line speed and can connect to Aurora’s Visualize™ quality control system for integration of measurements with process tools to provide real-time 3D visualization of intra-tool dynamics, both spatially and by batch. This enables optimization and control of PVD or RPD processes for maximum production line yield and throughput.

Availability

The DM-121 and DM-321 products are available now, and can be seen at the Shanghai New Energy Conference Exhibition (SNEC), May 28-30, booth number E3-653.